In recent years, the dissemination of information networks, particularly the Internet, have been striking. W.W.W (World Wide Web) among others is essential for services not only for businesses but also for general home users. W.W.W is services allowing a reception terminal to access a variety of content (home pages) existing on the Internet and obtain necessary information.
In recent years, general users also use W.W.W as a tool for not only collecting content but also for enjoying the content rich in entertainment or presenting their own content. It is expected that the number of users is increasing more and more in the future.
W.W.W is a software architecture developed by the CERN (Conseil Europ'en pour la Recherche Nucl'aire) in 1989. W.W.W is the communication system constituted of a software group constituted of a so-called HTTP (HyperText Transfer Protocol) server and an HTML (HyperText Markup Language) browser interconnected by the Internet, and is supported by software HTTP and HTML. HTTP is the communication protocol between an HTTP server and an HTML browser, and HTML is the format of (homepage) data exchanged between an HTTP server and an HTML browser.
FIG. 1 shows a mechanism of producing a W.W.W content (homepage) of this type.
As shown in FIG. 1, in a W.W.W system 1, a reception terminal 11 and an HTTP server 13 are interconnected by the Internet, the reception terminal being constituted of an HTML browser 22 and a platform 21 made of a predetermined OS (Operating System), hardware and the like.
Description will be made on a process of reproducing content on the HTTP server 13 by the reception terminal 11.
Upon reception of an URL (Uniform Resource Locater) of a homepage from a user as shown by an arrow 31, the HTML browser 22 of the reception terminal 11 accesses the HTTP server 13 designated by the input URL via the Internet 12 as shown by an arrow 32 to request for the data of the homepage designated by the URL.
In response to the request, the HTTP server 13 transmits the data file (hereinafter called an HTML document) 33-1 of the homepage described in the HTML format via the Internet 12. The HTML browser 22 of the reception terminal 11 displays the received HTML text 33-1 on a display (not shown) of the reception terminal 11, for example, in the format of a display 34. The HTML browser 22 acquires related data 33-2 such as a bitmap file (image file), when necessary, from the HTTP server 13, and displays it in a predetermined area of the display 34.
The HTML browser 22 is therefore essential software for general users utilizing W.W.W. HTML has been developed in order for researchers to share text data such as technical documents via information networks, and has distinctive characteristics that documents are structured by using an approach called Markup.
FIG. 2 shows an HTML text and its display example.
In the HTML text 33-1, the portion sandwiched between “<” and “>” is called a tag which is used for Markup.
The contents of the portion sandwiched between HTML tags (<HTML> and </HTML>) indicate HTML data. The portion sandwiched between BODY tags (<BODY> and </BODY>) indicates the main text of the document. A portion 41 “<H1>PLEASANT FOOD SHOP IN KAMAKURA</H1>” sandwiched between H1 tags (<H1> and </H1>) indicates that the character string “PLEASANT FOOD SHOP IN KAMAKURA” is a headline of the document. Portions 42 and 43 sandwiched between P tags (<P> and </P>) indicate sentences of the documents. Standardization of such tag types is managed by W3C (World Wide Web Consortium).
A display 34 provides the content in conformity with the structure of the HTML document 33-1.
A character string corresponding to the portion 41 sandwiched between H1 tags is displayed in the upper area 51 of the display 34, a sentence corresponding to the portion 42 sandwiched between the P tags is displayed in the lower area 52, and a sentence corresponding to the portion 43 sandwiched between the P tags is displayed in an area lower than the area 52.
Since the HTML document 33-1 is expressed by text, HTML is not dependent upon a platform such as OS. Since HTML is a text format, a user and the like can create a content in a relatively straightforward manner by using HTML with some learning.
HTML can insert an image into a document by using <IMG> tags. For example, an image 33-2 is displayed in an area 54 in the area 52 of the display 34, the image 33-2 corresponding to an image file (food.jpg) corresponding to a portion 44 sandwiched between <IMG> tags in the portion 42 sandwiched between the P tags in the HTML document 33-1.
Since HTML is provided with tags for expressing media other than the text, HTML can deal with a combination of a plurality of media such as texts, images (still images and moving images) and audio. The content of this type is hereinafter called a multimedia content. Therefore, most of W.W.W data known as so-called homepages are a multimedia content.
As above, since HTML is characterized in that it does not depend upon a platform, it can deal with multimedia information, and it can create content in a relatively straightforward manner.
Services for distributing a multimedia content are prevailing and HTML derivative technologies have been adopted in information networks for digital electronic home appliances such as mobile phone networks and digital broadcasting, in addition to the Internet. For example, BML (Broadcast Markup Language), Compact HTML and the like are known, BML being adopted for data broadcasting services of BS (Broadcasting Satellite) and Compact HTML being used by the i-mode for mobile phones by the NTT DoCoMo, Inc. These services are often supplied nowadays on the assumption that they are used only by particular digital home electronic appliances or particular information networks, and mutual distribution of content is not possible or limitative.
It is expected in the future that all digital electronic home appliances including computers are interconnected by one information network. In such a case, it is requested that any terminal can receive services of the same content and that the content is highly entertaining, has sophisticated functions, high performance as well as being apt to be developed under reduced cost.
As described earlier, however, HTML has been developed in order for researchers to share text data, and is not developed as a system for satisfying the needs expected to become essential in the future. As solutions for satisfying such needs, HTML has therefore the following issues left to be solved.
Namely, as described above, HTML is the format for expressing a structured document, i.e., text media. In HTML, therefore, media (images and the like) other than the text is inserted into a text (document).
However, if other media are inserted into a document, there arises a first issue that consistency of presentation is not guaranteed.
More specifically, although the position of media inserted into a text is determined by the text layout, the text is returned when it reaches the end of the window (for example, as shown in FIG. 2, in the area 52 of the display 34, the text is returned at “PASTER HOUSE” and the following “HAS BEEN FOUND” is displayed in the next row). The display position of media is not determined therefore until the window size of an HTML browser is determined (until a user displays content).
A display 34-1 shown in FIG. 3 and a display 34-2 shown in FIG. 4 are examples of presentations having different media display positions because of different window sizes, even with the same HTML document, i.e., the displays are examples of presentations not guaranteeing presentation consistency.
In other words, although a layout method of a display by HTML is a suitable method of displaying media such as images as part of a document, it is not a suitable method of displaying a combination of various media as a multimedia content.
The reason for this is that considerable attention is paid to the design of a multimedia content in many cases, and that a content creator often desires that the positions of respective media to be presented can be designated by absolute values and the content of the same design can be presented irrespective of the window size of an HTML browser. Namely, the content creator does not desire to display differently the created multimedia content as in the display 34-1 (FIG. 3) or display 34-2 (FIG. 4) depending upon the window size of an HTML browser. The content creator desires that, as shown in a display 34-3 of FIG. 5 each of a title text, two main texts and an image is displayed by designating the absolute positions (in the example of FIG. 5, absolute values from the upper left corner) of the fixed coordinate system of the display 34-3.
In addition, since the HTML format defines only the text structure, the layout details such as a font type, a space between characters and a space between rows, a hyperlink expression method (although expression is made often by using blue fonts and underlines, definitions thereof do not exist) and the like are fundamentally dependent upon an HTML browser, when HTML data is actually displayed. If the same HTML document is presented by HTML browsers developed by different vendors, it may be displayed minutely different. This shows that presentation consistency is not guaranteed.
Under such circumstances, CESS (Cascading Style Sheets) has been proposed as a mechanism of designating the style of an HTML document. By utilizing CESS, it is possible to unanimously designate the layout of a text. However, CESS is used persistently for the layout of a document, HTML browsers of companies support in different manners and as will be later described, CESS does not provide services for 3D (3 Dimensional). Further, CESS has its own grammar (different from HTML) and content creators are required to be familiar with it.
As above HTML is associated with the first issue that presentation consistency is not guaranteed which is the essential condition of multimedia expression.
Further, HTML is associated with a second issue that no synchronizing mechanism between media is provided, from the view point of multimedia expression.
The synchronizing mechanism between media is a means for controlling the presentation timings when a combination of media having a time axis, such as audio, moving images and animation, is presented. Use of the synchronizing mechanism between media allows expressions, for example, reproduction of animation synchronized with music and concurrent or continuous reproduction of a plurality of moving images. As above, the synchronizing mechanism between media is a function essential for realizing a multimedia content.
Further, HTML is associated with the third issue that there is no compatibility of the content between different types of apparatuses (e.g., between a personal computer and a digital electronic home appliance).
Namely, although HTML has no specification regarding the interface for manipulating a content, many HTML browsers on personal computers are realized by the interfaces of personal computers, e.g. by a window provided by the Windows (registered trademark) OS.
Since the size of a window can be changed, the size of an HTML browser can also be changed. Namely, the size in a browser horizontal direction is not definite so that the content unable to be displayed is developed downward and not displayed. In order to display it, a scroll in the vertical direction is used. A mouse is used for a content manipulation such as a jump to another HTML document through hyper link. A content is created on the assumption of a manipulation performance dependent upon the personal computer.
In contrast, although an HTML text can be displayed on a digital electronic home appliance, the display size of an HTML browser is generally fixed and a scroll function is not provided in some cases. Since it is necessary to be accustomed to the manipulation of a moving cursor such as a mouse, the moving cursor is considered unsuitable for electronic home appliances, so that the function corresponding to a mouse is not provided in many cases. Therefore, when HTML is applied to digital electronic home appliances, the HTML format is generally modified or extended in some way, in order to allow the interface of a digital electronic home appliances to use HTML.
This difference between a personal computer and a digital electronic home appliance results in a possibility that compatibility is not ensured if an HTML content distributed on the Internet is distributed to a network of digital electronic home appliances. In order to absorb this difference, conversion software is used in a partial field. Since an HTML content on the Internet is created based upon an interface of a personal computer as described above, even if the HTML content converted by the conversion software is produced, the content may become meaningless presentation.
As above, HTML is associated with the third issue of no compatibility between contents.
HTML has also a fourth issue of a limit in function extension.
Namely, as described above, HTML is primarily structured document data and is not an application program. An HTML browser can therefore display only the data prepared in an HTTP server. The types (media) of data capable of being displayed is limited to only those defined by the HTML format.
For example, when newly developed media are used, it is necessary to perform extension of the media with regard to the HTML format standardized by the above-described W3C. In order also for the media to be used, the HTML browser of each company is required to support a software module for reproducing the new media and correctly recognize the extended portion, i.e., tags.
However, in practice, the HTML browser of each company extends tags often in an independent manner, and there may be no compatibility between these browsers. Also in some cases, an HTML content itself is dependent upon specific extension of a particular HTML browser.
There is a plug-in function as another method of extending the function of an HTML content. A plug-in is a software module of extending a function of an HTML browser. If a plug-in realizing an optional function is installed in an HTML browser, this function can be executed by HTML content. However, in order for a user to use the plug-in, it is necessary to perform in advance its download, install and upgrade. The plug-in is required to be developed for each of OSes and browsers, and the HTML browser not supporting the plug-in cannot display the HTML content using the plug-in.
More correctly, the extension function by a plug-in incorporates the mode that another application runs in a partial region of an HTML content, and the function is not contained in the content itself and the HTML itself is a structured document unchangeably.
There is Java(R)Script as an extension aiming at making an HTML document itself execute an optional logic. Java(R)Script is a script language, and similar to a C language and a Java(R) language, has a grammar considering that even a content producer such as a designer and a content creator can write in a relatively straightforward manner, while supporting the control structure such as conditional branch and iteration. Code of Java(R)Script is characterized by ease of use such as not requiring advanced compilation since it is executed by an interpreter. Since Java(R)Script places importance to use easiness, it is inferior to the C language and Java(R) language in terms of an execution performance, a program size and program structuralization.
From these reasons, although Java(R)Script is suitable for media and a plug-in provided by HTML and a relatively simple application such as manipulating a browser itself, it is often unpractical to realize a complicated function (e.g., decoding particular media, and GUI components) by Java(R)Script itself.
As above, HTML is associated with the fourth issue of a limit in its extension function.
HTML has also a fifth issue of inferior productivity of content.
Namely, as described above, HTML has been developed in order to allow researchers to share structured document data. Being limited to the usage of this kind, it can be said that writing a content with a tool such as a text editor in accordance with the HTML format is a relatively easy work for researchers well grounded in software.
In contrast, when designers and creators form a content which is rich in entertainment and complicated, it is rare that an HTML document is written directly by using a text editor or the like, but dedicated authoring software is generally used. This software presents a graphical content forming environment so that the content having a relatively complicated layout can be formed without knowledge of HTML.
The HTML format itself is, however, not designed by considering affinity with the authoring software. Harmful influences of this include an overhead of a data size to be caused by the software mechanically forming an HTML document, difficulty in compatibility between authoring software and in fine adjustment at the content finishing stage, low readability of formed HTML documents, and the like, thus leading to the situation that advantages of HTML become rather disadvantages.
As described earlier, when the extension function is mounted in an HTML content, a script language such as Java(R) Script is often used and designers and content creators often write code of Java(R)Script by themselves even for a more or less complicated content.
However, from the viewpoint of content productivity, the extension functions of this type are preferably developed by programmers having high skills of software by using a program language such as a C language and a Java(R) language. Also from the viewpoint of content productivity, it is preferable that designers and creators pay attention to how the extension functions are customized and combined and which kind of services are realized, and that the script language such as Java(R)Script is used when designers and content creators combine and control these extension functions.
However, presently, specialization in the production of an HTML content is still not established, and in addition the HTML format itself is not designed by considering affinity with development flows of this type.
From the viewpoint of content productivity, although the extension function once developed should be reused, it cannot be said that the script language such as Java(R)Script sufficiently supports the function regarding software modularization (easy to customize, capsulated mount, software module distribution and the like), and it is therefore difficult to reuse.
As above, HTML has the fifth issue of inferior content productivity.
HTML has also a sixth issue of difficulty in sufficient manifestation of a hardware performance.
Specifically, it is expected that the function and performance of hardware of digital electronic home appliances including personal computers are improved more and more in the future. There is a large possibility that highly sophisticated 3D graphics functions as realized in some home games, among others, are adopted in other products in the near future.
In contrast, HTML is software aiming primarily at sharing structured documents, and is unsuitable for expressing a content assuming 3D. As described above, although it is possible to extend the function of an HTML content by using a plug-in or a plug-in such as Java(R)Script, they are associated with the above-described issues and HTML is not always a proper solution to manifest the expected hardware performance that digital electronic home appliances have in the near future.
As above, HTML is a software architecture developed in order to meet the needs of sharing document data among researchers. From the viewpoint of sharing document data, it can be considered that HTML is one of the most refined solutions even at the present time. However, the needs of content distribution on present information networks are sophisticated-function-orientated and multimedia-orientated, and it is required that content producers of an occupation type such as designers and content creators can produce a content in a straightforward manner.
In order to deal with a change in the needs of this kind, although extension of various functions has been made heretofore to HTML, since it does not follow the design idea inherent to HTML, the fundamental solution is still not reached in the context of content compatibility, productivity and the like and HTML is associated with the above-described first to sixth issues.